JP5509498B2 - Battery having air electrode and biasing lever gasket - Google Patents

Abstract

A fluid consuming battery and method are provided for reducing electrode doming and providing an adequate sealed closure to the battery housing. The battery includes a cell housing having first and second housing components and at least one fluid entry port through a side of the cell housing for the passage of a fluid. The battery also has a gasket disposed between the first and second housing components. A first electrode is disposed within the cell housing in electrical contact with the first housing component and a second air electrode is provided in an electrode assembly disposed within the cell housing in electrical contact with the second housing component. The electrode assembly includes a first peripheral portion that is pre-compressed relative to a middle portion. The gasket has first and second extensions that bias against interior surfaces, and the second extension is radially inwards of an angled outward recess in the can.

Description

  The present invention relates generally to hermetic closure of electrochemical batteries, and more particularly to hermetically closing battery cells having fluid consuming electrodes such as air depolarized cell batteries that prevent or reduce cell leakage and electrode assembly doming. About.

  Electrochemical battery cells that utilize fluids such as oxygen or other gases from the outside of the cell as an active material that generates electrical energy, such as air depolarized battery cells, to power various portable electronic devices Can be used for Zinc / air cells are typically assembled in the form of button cells with particular utility as batteries for electronic hearing aids and other electronic devices. Zinc / air button cells typically include a cathode can and an anode cup or anode cover, which together form a cell housing. A positive electrode and a negative electrode (a cathode and an anode, respectively), a separator, and a water-soluble electrolyte are disposed inside the cell housing. In an air depolarization cell, the positive electrode is generally a sponge-like porous air electrode. A gasket is disposed between the first and second housing components to hermetically close the cell housing. An opening is typically provided in the cell housing to allow the oxygen containing atmosphere to enter the air cathode to function as the cathode reactant.

  In a zinc / air cell, the air electrode is typically provided as an electrode mixture of carbon, polytetrafluoroethylene (PTFE) resin powder, manganese dioxide, and binder pressed into a current collector screen. A microporous layer, such as a microporous PTFE film, is usually bonded to the air intake side of the air electrode, allowing air to enter the air electrode mixture. The air electrode with current collecting screen, the microporous layer, and the separator are typically assembled together as an air electrode assembly, typically in the form of a laminated sheet. The air electrode assembly is inserted into the housing such that the periphery of the electrode assembly is compressed with the gasket between the housing components when the cell housing is crimped closed. The air electrode assembly is generally flexible and sponge-like and includes a porous material that compresses with the gasket to provide a hermetic closure of the cell housing.

  Conventional insulating gaskets are generally J-shaped gaskets having an outer upright wall, a shorter inner upright wall, and an interconnected bottom base wall. The outer upright wall of the gasket is typically compressed between the side walls of the two housing components. The base wall of the gasket is typically compressed between the bottom edge of the side wall of the anode cup or anode cover and the air electrode assembly, which then abuts the cathode can. The inner upright wall of the conventional J-shaped gasket extends into the internal volume of the cell housing so that it consumes the volume in the battery and does not necessarily provide optimal sealing engagement.

  Conventional electrochemical cells that use porous electrode assemblies are believed to have several disadvantages. For example, the crimp closure of the battery housing typically produces an axial force on the can and gasket that is transmitted to the gasket and air electrode assembly interface. Since the air electrode assembly is typically manufactured with a high porosity, the air electrode assembly is not a rigid member and therefore does not necessarily provide a robust hermetic closure. During the crimp closure of the battery housing, the air electrode assembly is compressed, which usually causes doming of the air electrode assembly towards the anode, which is an undesirable non-flat state. Doming of the air electrode assembly generally results in a loss of otherwise usable internal volume in the battery cell, may cause cracking of the air electrode assembly and cause electrolyte leakage from the battery cell There is a case.

  Accordingly, it is desirable to provide a battery cell that optimizes the usable internal volume of the battery housing for the active material. In particular, it is desirable to provide an air cell that minimizes the doming of the air electrode assembly. In addition, it is desirable to provide a battery cell that further exhibits enhanced leakage prevention to ensure a reasonable long shelf life of the battery cell.

  In accordance with the teachings of the present invention, a battery is provided that provides a moderate hermetic closure to the battery housing. According to one aspect of the invention, a battery is provided that includes a cell housing that includes first and second housing components and a gasket disposed between the first and second housing components. The cell housing has at least one fluid inlet port that passes through a side of the cell housing for passage of fluid into the cell housing. The battery includes a first electrode disposed in the cell housing in electrical contact with the first housing component, and a first electrode disposed in the cell housing in electrical contact with the second housing component. And an electrode assembly including two fluid consuming electrodes. The gasket extends such that the outer upright wall, the base wall, and the first inner wall biasingly contact the first housing component and the second inner wall biasingly contact the electrode assembly. First and second inner walls.

  According to another aspect of the invention, a battery is provided that includes a cell housing having at least one fluid inlet port that passes through a side of the cell housing for passage of fluid into the cell housing. The cell housing includes a first housing component and a second housing component. The first electrode is disposed in the cell housing in electrical contact with the first housing component. An electrode assembly including a second fluid consuming electrode is disposed in the cell housing in electrical contact with the second housing component. The gasket is disposed between the first and second housing components. The gasket includes an outer upright wall, a base wall, and first and second inner extensions extending from the base wall and having a termination, the first and second inner extension walls being a first inner wall. The wall is compressed so that it is in urging contact with the first housing component and the second inner wall is in urging contact with the electrode assembly.

  In accordance with one or more of the various aspects of the present invention, the battery advantageously achieves an enhanced hermetic closure of the cell housing. Further, the battery exhibits reduced doming of the electrode assembly that may otherwise consume the usable volume in the battery.

  These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

1 is a perspective top side view of a square air cell battery configured in accordance with a first embodiment of the present invention. FIG. FIG. 2 is a perspective bottom side view of the square battery seen in FIG. 1. It is a disassembled perspective view of the square battery shown in FIG. It is an expanded sectional view of the square battery obtained through the IV-IV line of FIG. FIG. 2 is a top view of an air electrode assembly (free microporous layer not shown) used in the prismatic battery of FIG. 1. FIG. 6 is an enlarged cross-sectional view of the air electrode assembly and free microporous layer obtained through line VI-VI in FIG. 5. FIG. 2 is an elevational side view of a press assembly machine for pre-compressing and cutting an air electrode assembly for use in the cell seen in FIG. 1. FIG. 3 is an elevational side view of a press assembly machine that further illustrates compression and cutting of the air electrode assembly. FIG. 6 is a side view of a pre-compressed air electrode assembly waiting for insertion into a cell housing. FIG. 4 is an enlarged cross-sectional view of the gasket obtained through line XX in FIG. FIG. 3 is a cross-sectional view of a rectangular battery that further illustrates a high compression region of a gasket according to one embodiment. It is an enlarged view of the cross section XII shown in FIG. FIG. 3 is an exploded cross-sectional view of a battery further illustrating the application of sealant on various surfaces according to one embodiment.

  Embodiments of the present invention include a battery that includes an electrochemical cell that utilizes a fluid (such as oxygen or another gas) from the outside of the cell as an active material for use with one of the electrodes. The battery cell has a fluid consuming electrode, such as an oxygen reducing electrode, that uses a fluid (eg, oxygen) received from the outside of the cell as the electrochemically active component. The battery cell may be an air depolarization cell or an air assisted fluid utilization cell. Although the present invention is illustrated below with an air depolarization cell having an oxygen reduction electrode, the present invention can be used more generally in fluid consumption cells having other types of fluid consumption electrodes. Further, although the exemplary cell is shown as a rectangular cell having a substantially rectangular shape, the battery cell can be of other shapes and sizes, such as a cylindrical or button cell.

  Referring now to FIGS. 1-4, an electrochemical fluid consumption battery cell 10 is shown configured according to one embodiment of the present invention. As shown, the fluid consuming cell 10, which in this embodiment is an air depolarizing cell, has a first housing component 16 called an anode cup or cover and a second housing component 14 called a cathode can. A cell housing 12 is included. The can 14 and cover 16 may be of other shapes and sizes that are otherwise different from what would be considered a can or cover. For the disclosed example, the first housing component is referred to below as cover 16, while the second housing component is referred to below as can 14. Both can 14 and cover 16 are made of a conductive material and are electrically separated from each other by gasket 22. The can 14 generally functions as an outer positive contact terminal for the fluid consuming cell 10, while the cover 16 generally functions as an outer negative contact terminal.

  The can 14 includes a centrally recessed bottom surface having a transition portion 30 between the peripheral portion and the recessed central portion. A plurality of fluid inlet ports (holes) 32 are formed in the bottom of the can 14 such that fluid (atmosphere containing oxygen) enters the interior of the cell housing 12 and is assembled as part of the electrode assembly 24. It is possible to move to 52. It should be appreciated that one or more fluid inlet ports 32 can be used that allow sufficient fluid containing the cathode reactant (eg, oxygen) to reach the fluid consuming electrode 52. is there. Further, a fluid conditioning system can be incorporated into or outside the battery cell 10 to regulate the rate of fluid inflow into the battery cell 10.

  A first electrode, also referred to as a negative electrode or an anode, is disposed inside the cell housing 12. Also disposed within the cell housing 12 is an electrode assembly 24 that includes a second fluid consuming electrode 52 (FIG. 6). The second electrode 52 is also referred to herein as a positive electrode or a cathode. A separator 50, also shown as part of the electrode assembly 24, is disposed between the first electrode 34 and the second electrode 52. The separator 50 functions as an ionic conductor between the respective electrodes 34 and 52. The separator 50 also functions as an electric dielectric for preventing an internal short circuit between the electrode 34 and the electrode 52. In one embodiment, the separator 50 has two layers, although one or more layers of separator material can be used.

  The first electrode 34 is preferably in electrical contact with the cover 16. According to one embodiment, the first electrode 34 is a zinc electrode housed in an anode cup or cover 16 having zinc as the anode electrochemically active material. The electrode 34 can include zinc powder placed in the cup 16 and makes electrical contact with the anode cup or cover 16. In one exemplary embodiment, the first electrode 34 can include a mixture of zinc powder, a water-soluble electrolyte, and an organic component such as a binder, which constitutes the negative electrode of the battery cell 10. . The water-soluble electrolyte can include an aqueous potassium hydroxide solution, which is a 30 percent (30%) potassium hydroxide (KOH) solution according to one example. The first electrode 34 can include other known materials for providing a negative electrode. In the disclosed embodiment, all the electrochemical active materials of the negative electrode 34 are combined and accommodated inside the housing 12 when the cell is assembled.

  In contact with the bottom surface of the first electrode 34 is an air electrode assembly 24 that includes a separator 50 attached (eg, bonded) to the air electrode 52. The air electrode assembly 24 is shown formed as a laminated sheet that is combined, compressed, cut, and then inserted into the cathode can 14 approximately along the bottom inner surface. The air electrode assembly 24 includes a peripheral region or portion 28 that is compressed and then disposed between the gasket 22 and the inner peripheral surface of the bottom of the can 14. The air electrode assembly 24 is further shown in FIGS. 5 and 6 having a generally square or rectangular shape with rounded corners so that it fits inside the similarly shaped can 14. In the embodiment shown and described herein, the air electrode assembly 24 includes a separator 50, an air electrode 52, a current collector screen 54 disposed within the air electrode 52, and a layer of air permeable and porous material. 56. The air assembly 24 is typically formed as a laminated sheet composed of various layers that allow for easy insertion and assembly into the electrochemical cell 10.

  The air electrode 52 is made of a cathode mixture of carbon, catalyst, and binder as is known in the art. According to one exemplary embodiment, the positive electrode mixture is carbon in an amount of about 60 percent (60%) to about 80 percent (80%) of the total mixture, about 3 percent (3%) to about 12 percent of the total mixture. Manganese oxide catalyst in an amount of percent (12%) and tetrafluoroethylene (TFE) binder in an amount of about 5 percent (5%) to about 40 percent (40%) of the total mixture are used. According to another embodiment, the air electrode 52 mixture preparation uses 10 percent (10%) to 15 percent (15%) TFE binder. The current collector 54 may include a nickel exmet screen disposed within the air electrode 52 or embedded extending to the periphery of the electrode assembly 24 on one side of the positive electrode mixture 54, preferably on the side adjacent to the separator 50. it can. The air cathode 52 is preferably in electrical contact with the can 14. Electrical contact can be made primarily by the current collector 54, preferably as a result of an interference fit between the outer edge of the electrode assembly 24 and the inner surface of the can sidewall 18. Carbon is activated carbon, which functions as an active electrochemical substance for the air electrode 52. Furthermore, an outer fluid such as oxygen also functions as an active component of the air electrode 52, which reacts with the water in the air electrode on the surface of the activated carbon, catalyzed by manganese oxide. As a result, the air electrode 52 uses the active ingredient received from the outside of the cell battery 10.

  An air distribution or diffusion layer 60 is disposed between the air electrode assembly 24 and the bottom inner surface of the can 14. The air diffusion layer 60 may include a highly porous free layer, such as low density paper, that enters the opening 32 and reaches the air electrode assembly 24, particularly the air electrode 52, particularly oxygen, especially oxygen. Facilitates uniform distribution. In the illustrated embodiment, the air diffusion layer 60 is not formed as part of the assembly 24 and does not extend within the compressed crimp closure region between the gasket 22 and the can 14.

  The air electrode assembly 24 is a substantially flexible, sponge-like porous sheet made of a porous material. The air electrode 52 is manufactured with a high degree of porosity to achieve enhanced electrochemical operation. The microporous layer 56 can be a PTFE film layer that is substantially porous that allows controlled passage of air. The microporous layer 56 is also hydrophobic to specifically resist the passage of the water-soluble electrolyte so as to control the entry and exit of the liquid. According to one embodiment, the microporous layer 56 is pressure laminated to the bottom surface of the air electrode 52.

  Another air permeable microporous layer 58 can be disposed in the cell 10 between the electrode assembly 24 and the can 14. According to one embodiment, the microporous layer 58 can be a free layer of PTFE film that is placed under the microporous layer 56, eg, the cell 10 when the layer 56 is damaged by cracks or otherwise. Provides an additional barrier to electrolyte leakage from the

  The air electrode assembly 24 is generally configured as a laminated sheet that is pre-compressed in the surrounding region 28 prior to insertion into the cell housing 12. As used herein, a “pre-compressed” air electrode assembly 24 is a peripheral portion 28 of the assembly after its component stacking and before the electrode assembly 24 is inserted into the can 14. Is to be compressed. The air electrode assembly 24 has a substantial intermediate area or portion 26 that remains uncompressed relative to the compressed peripheral portion 28. The uncompressed intermediate portion 26 remains sponge-like, flexible and porous, accepts outside air (eg, oxygen) entering the opening 32 and is in ionic communication with the anode 34 through the separator 50. The peripheral compression portion 28 is compressed in a peripheral region where the air electrode assembly 24 will be disposed between the bottom base wall 42 of the gasket 22 and the peripheral portion of the inner bottom surface of the can 14. There may be a transition zone between the compressed peripheral portion 28 and the uncompressed central portion 26 where the electrode assembly 24 is partially compressed to prevent damage to the electrode assembly.

  The width of the compressed portion 28 is selected to increase the circumferential strength of the air electrode assembly 24, whereby the radial closing force can be absorbed by the hard pre-compressed portion 28, and the more porous uncompressed portion 26. It is not transmitted further to the inside. As a result, doming of the air electrode assembly 24 is reduced. The size of the pre-compressed portion 28 of the assembly 24 can be balanced between increased leakage prevention, any adverse effects of electrode doming, and reduced electrochemical function.

  According to one embodiment, the compressed portion 28 of the air electrode assembly 24 is compressed at least 20 percent (20%) of the initial thickness, which is the thickness of the uncompressed portion 26. According to the example of a PR48 battery cell having an overall length of about 25 millimeters and a width of 7.5 millimeters, the air electrode assembly 24 has a starting uncompressed height of about 0.015 inches. Formed. After pre-compression of the surrounding portion 28, the uncompressed portion 26 of the air electrode assembly remains approximately 0.381 millimeters (0.015 inches) thick and the compressed portion is approximately 0.2921 millimeters (0.0115). Inch). Accordingly, the compressed portion 28 is compressed by more than 0.0508 millimeters (0.002 inches), and more specifically by about 0.0635 millimeters (0.0025 inches). To achieve a compression thickness of about 0.02921 millimeters (0.00115 inches), according to one example, the compression portion is capable of rebounding back by about 0.0127 millimeters (0.0005 inches). Thus, it can be initially compressed to about 0.2794 millimeters (0.0110 inches).

  By pre-compressing the surrounding portion 28, subsequent crimp closure within the housing 12 results in energy toward compression of the gasket 22 as opposed to applying significant energy for compression of the air electrode assembly 24. become. This is because the pre-compressed portion 28 has been removed from flexibility and is very stiff. The pre-compressed portion 28 further retards the movement of the water-soluble electrolyte, which reduces the access of the water-soluble electrolyte to the surroundings, and thus further reduces the leakage of the battery cell 10. This compression of the portion 28 causes at least compression of the void space within the porous material 52 and the microporous layer 56 and results in some compression of the separator 50. It can also be seen that as a result of the pre-compression of the compressed portion 28, most of the compressibility of the air electrode assembly 24 is removed prior to assembly of the assembly into the battery cell housing 12 and subsequent crimping closure of the housing 12. The peripheral portion 28 has been exposed and will exhibit a high degree of spring-like behavior, thereby providing a better axial seal within the sealed cell 10.

7-9, the manufacture of the pre-compressed air electrode assembly 24 is shown according to one exemplary embodiment. In FIG. 7, a press and cutting (punching) machine 90 is shown and accepts a pre-made sheet 51 of air electrode assembly material. The machine 90 has a generally square upper press 100 having a peripheral lower extension press portion 102 that is positioned on a lower press base 104 having a peripheral upper extension press portion 106 positioned on the extension portion 102. A support block 108 is provided around the outer edge of the base 104. As can be seen in FIG. 8, the upper press 100 is forced down and pre-manufactured air electrode to compress the sheet 51 between the press portions 102 and 106 to form the compressed region 28. It is moved into contact with the sheet of assembly material 51. According to one embodiment, the press 100 can apply a lamination pressure in the range of about 12.7 to 15.5 kg / cm ² (180 to 220 psi). According to an exemplary embodiment, the press portions 102 and 106 compress the sheet 51 at the top and bottom surfaces to form the compressed portion 28. According to other embodiments, the compressed portion 28 can be formed only on the top or bottom surface of the electrode assembly 24. In addition, excess sheet material 53 is cut by the corners of the support block 108 at the periphery of the compressed portion 28 so that the upper press 100 moves downward, thereby cutting the sheet 51 into the desired square shape and size. The The air electrode assembly 24 shown in FIGS. 5 and 9 then waits for insertion into the can 14 during assembly of the electrochemical cell 10.

  More than one air electrode assembly 24 can be cut from a single sheet 51 of laminate material. For example, the sheet 51 can be in the form of a strip from which a series of electrode assemblies 24 are stamped. Adjacent electrode assemblies 24 can have adjacent compression portions 28 formed by essentially simultaneous compression of at least a portion of both compression portions 28, such as using a single punch or roller.

  The electrochemical cell 10 advantageously uses an insulating gasket 22 having first and second internal extension walls or extensions 44 and 46 provided inside the crimp closure of the housing 12. Referring to FIG. 10, an insulating gasket 22 prior to insertion into the cell housing 12 is shown according to one embodiment. As can be seen, the gasket 22 includes an outer upstanding wall 40, a bottom base wall 42, and first and second inner extension walls 44 and 46 that form a pair of levers or legs. The first and second inner walls 44 and 46 have terminations and are interconnected to the outer upright wall 40 by a bottom base wall 42. The outer surface of the inner wall 44 is formed with a taper 45 of approximately 15 degrees (15 °) close to the terminal end, which allows a high degree of positioning with the cover sidewall 20.

  The first and second inner extension walls 44 and 46 are formed at an angle φ greater than 90 degrees (90 °), whereby the outer surface of the inner upright wall 44 and the bottom surface of the second inner wall 46 are 90 degrees. The angle φ is larger than (90 °). According to one embodiment, the angle φ ranges from 95 degrees (95 °) to 135 degrees (135 °), and more specifically about 100 degrees (100 °). The first inner wall 44 is an upstanding wall that is substantially parallel to the outer wall 40 so that the inner wall engages the inner surface of the lower extension wall 20 of the cover 16. The inner wall 44 and the outer upright wall have a slot 41 provided therebetween for receiving the side wall 20 of the cover 16. The second inner wall 46 is inclined downward from 5 degrees (5 °) to 45 degrees (45 °), more specifically about 10 degrees (10 °) from the horizontal, so that its bottom surface is the air electrode assembly 24. It is adapted to engage with the upper surface. By forming the first and second inner extension walls 44 and 46 at an angle greater than 90 degrees (90 °), the biasing force on the inner surface of the lower extension wall 20 of the cover 16 and the biasing force on the upper surface of the air electrode assembly 24. The first and second inner walls 44 and 46 of the gasket 22 are bent toward each other when the cell 10 is assembled. This provides a high degree of robustness to the sealing closure of the cell housing 12.

  The outer upright wall 40 of the gasket 22 has an inner surface 66 whose angle varies at location 64 to provide increased thickness at location 64. The change in angle at location 64 enhances the sealing closure and creates a highly compressed region at location 64. The resulting inner surface 66 of the upstanding outer wall 40 has a single change in angle at the position 64.

  In providing a single change in angle at location 64, there are no tool traces or inconsistencies associated with changes in the geometry of the inner surface 66 of the gasket 22. The outer surface of the outer upstanding side wall 40 may have various angles that result in ridges formed in the sealing zone when the cell housing 12 is crimped closed. Thus, the lower extended side wall 20 of the cover 16 can be pushed inward by a slightly greater sealing pressure within the sealing zone. At that time, the wall 20 of the cover 16 functions as a spring that provides a continuous force on the gasket 22 even during temperature changes. The upper part of the cover 16 is fixed by the remaining part of the cover 16 which becomes a negative contact surface. The bottom of the cover 16 is secured by a base 42 of the gasket 22 that holds the distal end of the wall 20 of the cover 16 in a radial position. This results in a cover sidewall 20 that is substantially held at both ends by a force applied to the center of the cover 16 (ie, in the sealing zone). The resulting spring loaded sealing members are preferred because they provide uninterrupted pressure on the sealing surface during temperature changes. Therefore, the leakage prevention property at the time of storage of the battery cell 10 can be improved. In addition, when the battery cell 10 is pressurized, such as during internal gas generation, this pressure acts on the inner cover sidewall 20 and thus enhances compression on the gasket 22 so that the gasket 22 is substantially Self-sealing.

  As seen in FIG. 11, the compressed gasket 22 includes a sealing zone in the barrel of the side wall near location 64, as well as the outer surface of the first inner extension wall 44 and the bottom surface of the second inner extension wall 46. A high compression seal zone 48 is created. Both radial and axial sealing zones are established, in particular with a high compression sealing zone 48. The plurality of sealed regions of the high compression zone 48 make the leakage path more serpentine and reduce the sensitivity of the main seal zone to manufacturing errors.

  In one example, the PR48 battery cell may use a can side wall 18 that is angled up to about 3.7 °. Thus, when the battery cell 10 is pulled again into the collet, the can side wall 18 becomes straight. The tightness between the inner diameter of the can 14 and the outer diameter of the gasket 22 is increased from clearance to a slight tightness.

  Referring to FIGS. 11 and 12, a second inner extension wall 46 is shown in relation to the bottom wall of the can 14, particularly the inner surface of the inclined transition 30 between the peripheral portion of the bottom wall and the central recess portion. ing. According to one embodiment, the distance D between the radially outermost point of the transition 30 and the radially innermost point of the contact between the second inner extension wall 46 and the air electrode assembly 24 (FIG. 12). Is greater than 0.127 millimeters (0.005 inches), and more specifically about 0.2032 millimeters (0.008 inches). The inner surface of the transition 30 in the can bottom preferably extends upward and outward from the central recess area at an angle greater than 15 degrees from the horizontal (when the cell is facing as shown in FIG. 11). The transition 30 in the can bottom may be a substantially straight ramp, a steep (eg, vertical) step, or a central portion of the electrode assembly 24 by the tip of the first inner extension 46 of the gasket 22. Other configurations that provide a recess that can be pushed into the interior can be included.

  By providing a second inner extension wall 46 of the gasket 22 that extends radially inward beyond the radially outermost point on the inner surface of the transition 30, the second inner extension wall 46 would otherwise occur. In order to reduce the amount of possible electrode assembly 24 doming, the electrode assembly 24 is essentially pressed downward. Thus, the second inner extension wall 46 of the gasket 22 essentially compresses the air electrode assembly 24 downward, causing the lever effect to oppose electrode doming by pressing the assembly 24 downward into the recessed can 14. . By forming around the outer periphery of the can 14, the lever effect can be generated on the air electrode assembly 24 in a downward direction.

  In general, the force applied to pre-compress the electrode assembly (pre-compression force) is better as long as the components of the electrode assembly 24 are not damaged, and the pre-compression force is applied during cell closure. Will generally be equal to or greater than the force applied to 24.

  Preferably, the pre-compressed portion 28 of the air electrode assembly 24 is not greater than 85% of the thickness of the central non-pre-compressed portion 26, more preferably not greater than 80%, more preferably greater than 75%. It is compressed to a thickness that is not large. In order to avoid damage to the electrode assembly, the thickness of the pre-compressed portion 28 will be compressed to a thickness that is not less than 70% of the thickness of the non-pre-compressed portion 26.

  As a result of the precompression, the rebound characteristics of the precompression portion 28 after the cell 10 is closed are reduced. The computer model predicts a bounce reduction ranging from an average of about 27 to almost 100% depending on the size of the electrode. Generally, the larger the electrode, the higher the effect of pre-compression. For electrodes having a width of about 15 mm or greater, preferably the pre-compression is such that when the electrode assembly 24 is removed from the sealed cell 10, the thickness of the pre-compression portion 28 does not increase by an average of more than about 12%. It can be determined by cutting the sealed cell 10 and measuring the thickness of the pre-compressed portion 28 before and after removing the electrode assembly 24 from the cut cell. More preferably, the increase in average thickness will not be greater than 10 percent and most preferably no greater than about 5 percent.

  The electrode assembly 24 can be pre-compressed before, during or after it is cut or stamped from a larger sheet 51 of laminated electrode assembly stock, but they are cut into individual electrode assemblies 24. It may be advantageous to pre-compress the peripheral portion of the adjacent electrode assembly 24 before By doing so, the side flow of the air electrode mixture 52 can be minimized, the compaction of the mixture during pre-compression can be improved, and the mixture during pre-compression from the end face of the cut electrode assembly 24 can be prevented. Is prevented.

  As an alternative to pre-compression of the surrounding portion of the electrode assembly 24 prior to insertion into the can, the electrode assembly 24 can be compressed before the gasket 22 and cover 16 are assembled with the can 14. For example, the electrode assembly 24 can be inserted into a can and a compressive force can be applied to the peripheral portion of the electrode assembly 24 using, for example, a rigid punch. In order to avoid damage to the electrode assembly 24 during the compression stage, it may be desirable to use a punch with an electrode assembly contact surface having a shape similar to that of the adjacent portion of the can bottom. It is also desirable to avoid protrusion of the cathode mixture 52 from the end face of the electrode assembly 24 during this compression stage. After the electrode assembly 24 is compressed, the gasket 22 and the cover 16 containing the anode 34 are combined with the can 14 and the upper end portion of the can side wall 18 is bent inward and downward to seal the housing 12.

  The pre-compression of the electrode assembly 24 prior to insertion into the can and the compression after insertion and prior to the combination of the can 14, gasket 22 and cover 16 can be performed only on the electrode assembly 24 or finely. This can be done to the electrode assembly 24 along with other cell components such as the porous layer 58. Inclusion of the microporous layer 58 in the electrode assembly 24 during compression prior to cell closure is advantageously reduced and the sealing properties of the microporous layer 58 are similarly improved.

  Compression of the seal-forming portion of the electrode assembly can provide a more robust seal in square and button-type fluid consuming cells as described above. Other shaped fluids, such as cylindrical cells, including cylindrical cells with similar compression of the electrode assembly disposed at one or both ends of the cell or with electrode assemblies disposed adjacent to the cylindrical sidewall of the cell It is also conceivable that a good seal can be provided in the consuming cell.

  Referring to FIG. 13, a zinc air cell battery 120 (an embodiment of the battery cell 10) is generally shown with sealants 122-136 on various surfaces. The electrochemical cell 120 uses a sealant that is added during cell assembly at one or more various locations within the cell 120. The sealant location can include a sealant 122 added to the top surface of the compression region 28 of the air electrode assembly 24 so that the sealant 122 is an interface between the air electrode assembly 24 and the bottom surface of the base wall 42 of the gasket 22. Is provided. Sealant 124 can be applied between the peripheral portion of air electrode 52 and the free layer of microporous material 56 of electrode assembly 24. Sealant 126 may be disposed between the peripheral portion of the free layer of microporous material 56 and the bottom of can 14. The sealant 130 can be disposed between the first inner extension 44 of the gasket 22 and the inner surface of the lower extension wall 20 of the cover 7. The sealant 132 may be disposed on the inner surface of the upper extension wall 18 of the can 14 that interfaces with the upstanding outer wall 40 of the gasket 22. The sealant 134 can be disposed on the inner surface of the upstanding wall 40 of the gasket 22 that interfaces with the lower extension wall 20 of the cover 16. Further, the sealant 136 may be disposed on the shoulder of the wall 20 of the cover 16 that interfaces with the upper inner surface of the upstanding outer wall 40 of the gasket 22.

  According to some examples, the various sealants 122-136 can include known sealants such as asphalt or polyamide hot melt adhesives. Various solvents such as trichlorethylene, isopropyl alcohol, naphtha, and other known solvents can be mixed with the sealant to facilitate the addition of the sealant. The weight load of sealant 122 to 136 in this mixture can be selected between 5 percent (5%) and 30 percent (30%), according to one embodiment. The various sealants 122 to 136 can be added using addition methods for sealants known in the art, such as spraying, droplet methods, hot melt dispensing methods, and the like. Neutralizing agents such as boric acid, citric acid, acetic acid, and others can be used to neutralize any potassium hydroxide leakage. By adding sealants 122 to 136 at various locations, dip coating of gasket 22 can be eliminated. This can lead to a reduction in manufacturing defects such as adhesive gaskets. Although sealants 122 through 136 are shown in this example, it should be appreciated that sealants 122 through 136 may not be required at all locations to provide a robust seal closure for cell 120.

  Thus, the battery cell 10 of the present invention advantageously provides a robust hermetic closure that minimizes electrolyte leakage and air electrode assembly 24 doming. The teachings of the present invention can be applied to battery cells configured in a variety of shapes and sizes, including square, cylindrical, disc-shaped, and other shapes.

  It will be understood by those skilled in the art and those skilled in the art that various modifications and improvements can be made to the present invention without departing from the spirit of the disclosed concept. The scope of protection afforded will be determined by the claims and by the breadth of interpretation that is legally acceptable.

14 Second housing component 16 First housing component 22 Gasket 24 Electrode assembly 34 First electrode

Claims (10)

At least one fluid inlet port passing through the cell housing for passage of fluid into the cell housing, the first housing component having a downwardly extending sidewall and a second housing component including a bottom surface. A cell housing having
A first electrode disposed in the cell housing in electrical contact with the first housing component;
An electrode assembly including a second fluid consuming electrode disposed in the cell housing in electrical contact with the second housing component;
A first inner wall disposed between the first and second housing components and extending to biasably contact the outer upright wall, the base wall, and the first housing component; A gasket including a second inner wall extending in biasing contact with the electrode assembly;
Including
The first and second inner walls have terminations and are interconnected to an outer upright wall by the base wall;
The first inner wall and the outer upright wall are provided with slots for receiving the downwardly extending side walls of the first housing component between the first inner wall and the outer upright wall. Engaging the inner surface of the side wall of the housing component of
The first and second inner walls in a non-deflection state form an angle between an outer surface of the first inner wall and a bottom surface of the second inner wall from 95 degrees to 135 degrees,
The outer surface of the first inner wall engages the downwardly extending side wall of the first housing component and the bottom surface of the second inner wall engages the upper surface of the electrode assembly; A battery characterized by that.   The battery according to claim 1, wherein the bottom surface of the second inner wall is inclined from 5 degrees to 45 degrees downward from the horizontal. According the first inner wall of the gasket is oriented to the inner surface of the first housing component, said second inner wall of the gasket, characterized that you have facing the electrode assembly Item 4. The battery according to Item 1. The battery according to claim 1, further comprising a separator disposed between the first electrode and the second fluid consumption electrode. The second housing component includes a bottom wall , the bottom wall being surrounded by the peripheral portion, a central recess recessed from the peripheral portion of the bottom wall , and the central recess and have a, a transition between the said peripheral portion,
The second inner wall has a surface that extends such that the electrode assembly is biased toward the central recess in the second housing component;
The battery according to claim 1. The second inner wall surface extends from the peripheral portion of the bottom wall of the second housing component toward the central recess, and from the transition portion of the bottom wall toward the central recess. battery according to claim 5, characterized in that extending a distance greater than 0.127 mm Te. The battery according to claim 5, wherein the central recess is recessed by an inclination of the transition portion.   The battery according to claim 1, wherein each of the first and second inner walls has a terminal portion. The battery of claim 1, wherein the gasket includes a change in the thickness of the outer upstanding wall that provides a high compression region between the first and second housing components .   The battery according to claim 1, wherein the second electrode is an air electrode.

Images